Effects of nuclear factor-kappaB on rat hepatocyte regeneration and apoptosis after 70% portal branch ligation

AIM： To detect the DNA binding activity of nuclear factor-kappaB （NF-KB） in rat hepatocyte and to investigate the effects of NF-KB on rat hepatocyte regeneration and apoptosis after 70% portal branch Iigation. METHODS： Sixty Wistar rats were randomly divided into control group and portal branch ligation group. The animals were killed 12 h, 1, 2, 3, 7, and 14 d after surgery to determine the contents of plasma ALT. Hepatocytes were isolated and nuclear protein was extracted. DNA binding activity of NF-KB was measured by ENSA. Hepatocyte regeneration and apoptosis were observed under microscope by TUNEL staining. The ultrastructural changes of liver were observed under electron microscope. RESULTS： Seventy percent portal branch ligation produced atrophy of the ligated lobes and the perfused lobes underwent compensatory regeneration, the total liver weight and plasma ALT levels were maintained at the level of sham-operated animals throughout the experiment. After 2 d of portal branch ligation, DNA binding activity of NF-KB in hepatocyte increased and reached its peak, the number of apoptotic hepatocyte in the ligated lobes and the number of mitotic hepatocyte in the perfused lobes also reached their peak. Typical apoptotic changes and evident fibrotic changes in the ligated lobes were observed under electron microscope. CONCLUSION： After 70% portal branch ligation, DNA binding activity of NF-KB in hepatocyte is significantly increased and NF-KB plays an important role in hepatocyte regeneration and apoptosis.

Influence of edaravone on Notch1 and nuclear factor-kappaB in rats with cerebral ischemia/reperfusion injury

BACKGROUND： It has been demonstrated that edaravone has a a neuroprotective role, inhibits free radical increase, and reduces celt apoptosis. The Notch pathway is a key factor in neurogenesis and cellular apoptosis The proinflammatory transcription factor nuclear factor-kappaB （NF-κB） plays an important role in inflammation and oxidation. OBJECTIVE： To observe the influence of edaravone on Notchl and NF-κB mRNA and protein expression in rats with focal cerebral ischemia/reperfusion injury. DESIGN, TIME AND SETTING： This randomized controlled neural and molecular biology experiment was performed at the Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, and the Chongqing Key Laboratory of Neurology between July 2007 and May 2008. MATERIALS： Thirty female Wistar rats were used. Edaravone was purchased from Jiangsu Xiansheng Pharmaceutical Limited Company, China. METHODS： Wistar rats were randomly divided into five groups （n = 6）. Thread was inserted into the internal carotid artery of the sham operation group but the middle cerebral artery was not ligated. A focal cerebral ischemia/reperfusion model was established by inserting thread into the right middle cerebral artery. The model rats in the edaravone groups were given tail vein injections of edaravone at 3 mg/kg body weight after ischemia for 2 hours and reperfusion for 12 or 24 hours. Ischemia/reperfusion groups （model group） received intravenous infusion of normal saline at the same volume as the edaravone groups after ischemia for 2 hours and reperfusion for 12 or 24 hours. MAIN OUTCOME MEASURES： The volume of the ischemic region was measured by 2,3,5-triphenyltetrazolium chloride staining. Notchl and NF-κB protein and mRNA expression were measured by immunohistochemistry and RT-PCR. Protein expression was represented by the absorbance value. RESULTS： Edaravone greatly reduced the focal infarct volume. Notchl and NF-κB protein and mRNA expression were rapidly upregulated following cerebral ischemia/reperfusion injury in model and edaravone groups compared with the sham operation group （P 〈 0.01 ）. In addition, edaravone treatment significantly upregulated Notchl expression but down-regulated NF-κB expression compared with model groups （P 〈 0.01）. CONCLUSION： Edaravone possibly protects brain tissue from ischemia/reperfusion injury by upregulating Notchl expression and regulating NF-κB expression.

Fruits extracts of Hovenia dulcis Thunb.suppresses lipopolysaccharide—stimulated inflammatory responses through nuclear factor—kappaB pathway in Raw 264.7 cells

Objective:To investigate the anti-inflammatory effects and the action mechanism of the fruits of Horenia dulcis(H.dulcis) in lipopolysaccharide(LPS)-induced mouse macrophage Raw 264.7cells.Methods:The extract of H.dulcis fruits(EHDF) were extracted with 70%ethanol.Mouse macrophages were treated with different concentrations of EHDF in the presence and absence of LPS(1 μg/mL).To demonstrate the inflammatory mediators including nitric oxide,inducible nitric oxide synthase and cyclooxygenase(COX)-2 expression levels were analyzed by usingin vitro assay systems.COX-derived pro-inflammatory cytokines including interleukin-1 β.tumor necrosis factor- α and prostaglandin F_2 were determined using ELISA kits.Cell viability,heme oxygenase-1 expression,nuclear factor-kappaB and nuclear factor F.2-related factors 2 translocation were also investigated.Results:EHDF potently inhibited the LPS-stimulated nitric oxide,inducible nitric oxide synthase.COX-2,interleukin-1 β and tumor necrosis factor- α expression in a dose-dependent manner.EHDF suppressed the phosphorylation of inhibited kappaB-alpha and p65 nuclear translocation.Treatment of macrophage cells with EHDF alone induced the heme oxygenase-1 and nuclear translocation of nuclear factor E2-reIated factor 2.Conclusions:These results suggest that the ethanol extract of H.dulcis fruit exerts its anti-inflammatory effects by inhibiting inhibited kappaBalpha phorylation and nuclear translocation of nuclear factor-kappaB.

Inhibitory Activity of Nuclear Factor-κB Potentiates Cisplatin-induced Apoptosis in A549 Cells

Whether inhibiting the activity of nuclear factor （NF）-κB potentiates cisplatin-induced apoptosis in non-small cell lung cell line A549 cells was investigated. The recombinant plasmid pcDNA3.1（＋）/IκBα expressing IκBα was constructed. The in vitro cultured A549 cells were transfected with pcDNA3.1 （＋）/IκBα alone, or pcDNA3.1（＋）/IκBα combined with cisplatin. The mitochondrial membrane potential （△ψm） was determined by rhodamine 123, the activity of caspase-3 was tested by colorimetric assay, and cell apoptosis was detected by flow cytometry with the annexin V/propidium iodide assay. The results showed that the activity of NF-κB in A549 cells was inhibited by transfecting pcDNA3.1（＋）/IκBα. Transfection of pcDNA3.1（＋）/IκBα alone did not promote apoptosis. Treatment of cisplatin alone had a little effect on cell apoptosis. Transfection of pcDNA3.1（＋）/IκBα combined with cisplatin treatment significantly induced apoptosis of A549 ceils. It was concluded that inhibiting the activity of NF-κB potentiated cisplatin-induced apoptosis of A549 cells.

Spliceosomal GTPase Eftud2 regulates microglial activation and polarization

Elongation factor Tu GTP binding domain protein 2(Eftud2)is a spliceosomal GTPase that serves as an innate immune modulator restricting virus infection.Microglia are the resident innate immune cells and the key players of immune response in the central nervous system.However,the role of Eftud2 in microglia has not been reported.In this study,we performed immunofluorescent staining and western blot assay and found that Eftud2 was upregulated in microglia of a 5xFAD transgenic mouse model of Alzheimer’s disease.Next,we generated an inducible microglia-specific Eftud2 conditional knockout mouse line(CX3CR1-CreER;Eftud2^(f/f) cKO)via Cre/loxP recombination and found that Eftud2 deficiency resulted in abnormal proliferation and promoted anti-inflammatory phenotype activation of microglia.Furthermore,we knocked down Eftud2 in BV2 microglia with siRNA specifically targeting Eftud2 and found that Eftud2-mediated regulation of microglial proinflammatory/anti-inflammatory phenotype activation in response to inflammation might be dependent on the NF-κB signaling pathway.Our findings suggest that Eftud2 plays a key role in regulating microglial polarization and homeostasis possibly through the NF-κB signaling pathway.

LITAF Promotes Atherosclerotic Plaque Formation by Stimulating the NF-κB Inflammatory Pathway

Objective Lipopolysaccharide-induced tumor necrosis factor-αfactor(LITAF)protein is a newly discovered inflammatory protein.This study aims to study the role of LITAF in the formation of atherosclerosis.Methods A total of 10 C57BL/6J mice and 10 C57BL/6J mice with knockout of LITAF gene(C57BL/6J–LITAF–)were divided into two groups:the control group and the LITAF^(−/−)group.The animals were accommodated for 16 weeks and then euthanized with their hearts and aortas isolated thereafter.Next,the roots of the mouse aorta were cryosectioned and stained with Oil Red O staining and immunohistochemical staining(CD68,α-SMA,and Masson),respectively.The area of Oil Red O staining and the proportion of positive expression after immunohistochemical staining were then compared between the control and LITAF^(−/−)groups.At the same time,the blood of mice was collected for the extraction of proteins and RNA.The proteins and RNA were used to detect the expression of major molecules of the NF-κB inflammatory pathway in mice in the control group and the LITAF^(−/−)group by Western blotting and RT-PCR.Results Oil Red O staining of the aortic root sections of the mice in each group revealed that the area of atherosclerotic plaques in the LITAF^(−/−)group was substantially lower than that in the control group(P<0.05).Moreover,immunohistochemical staining determined that the expression level ofα-SMA and CD68 in the LITAF^(−/−)group was significantly lower than that in the control group,whereas the results were reversed following Masson staining(P<0.05).The expression levels of P65 and caspase 3 were significantly lower in the LITAF^(−/−)group than in the control group(P<0.05),whereas the expression level of IκB was higher in the LITAF^(−/−)group.Conclusion LITAF might participate in the formation of atherosclerotic plaque through the NF-κB pathway and play a promoting role in the formation of atherosclerosis.

丁苯酞对急性缺血性脑卒中大鼠的脑保护作用及其机制

目的:探讨丁苯酞对急性缺血性脑卒中大鼠的脑保护作用,阐明其对急性缺血性脑卒中的治疗机制。方法: 48只SD大鼠随机分为假手术组、模型组(局灶性脑缺血大鼠模型)和丁苯酞组(局灶性脑缺血大鼠模型+丁苯酞治疗),每组16只。对各组大鼠进行神经症状评分测定,对大鼠脑组织进行HE染色,采用氯化三苯基四氮唑(TTC)测定脑梗死面积百分率,采用Western blotting法和逆转录-聚合酶链反应(RT-PCR)测定大鼠脑组织中肝细胞生长因子(HGF)、血管内皮细胞生长因子(VEGF)、基质金属蛋白酶2(MMP-2)、基质金属蛋白酶9(MMP-9)、核转录因子κB抑制蛋白α(IκBα)和核转录因子κB(NF-κB)亚单位p65(NF-κB p65)蛋白及mRNA表达水平。结果:假手术组大鼠脑组织无梗死灶形成,无神经功能缺损症状;与模型组比较,丁苯酞组大鼠脑梗死面积百分率和神经功能评分明显降低(P<0.01)。假手术组大鼠脑组织细胞结构完整、分布均匀;模型组大鼠脑组织大部分细胞坏死,胞浆破裂,细胞核破裂、凝缩;丁苯酞组大鼠脑组织少量细胞肿胀和坏死。与假手术组比较,模型组大鼠脑组织中HGF、VEGF、MMP-2、MMP-9和NF-κB p65蛋白及mRNA表达水平均明显降低(P<0.01),IκBα蛋白及mRNA表达水平明显升高(P<0.01);与模型组比较,丁苯酞组大鼠脑组织中HGF、VEGF、MMP-2、MMP-9和NF-κB p65蛋白及mRNA表达水平均明显升高(P<0.01),IκBα蛋白和mRNA表达水平明显降低(P<0.01)。结论:丁苯酞可改善急性缺血性脑卒中大鼠的神经功能,减少脑梗死面积,其机制可能与丁苯酞升高脑组织HGF水平,并通过干扰NF-κB信号通路而促进脑血管形成有关。

Influences of IL-6R Antibody on PMMA Bone Cement-mediated Expression of OPG and RANKL in Synovial Fibroblasts

Effect of interleukin-6 receptor （IL-6R） antibody on polymethyl methacrylate （PMMA） bone cement-mediated expression of osteoprotegerin （OPG） and ：receptor activator of nuclear fac- tor-kappaB ligand （RANKL） in synovial fibroblasts was investigated. Synovial tissue obtained from to- tal knee arthroplasty was digested and cultured. Inverted microscope was employed to observe the synovial cells and immunocytochemistry （SABC method） staining was used to identify synovial fibro- blasts. This experiment was divided into three groups according to different culture media： PMMA group （75μg/mL PMMA bone cement particles）, IL-6R antibody group （10 ng/mL IL-6R antibody＋75 μg/mL PMMA bone cement particles）, and control group （no IL-6R antibody or PMMA bone cement particles）. Influence of IL-6R antibody and PMMA on proliferation of synovial fibroblasts was meas- ured by cell counting kit-8 （CCK-8）. ELISA method was used to measure OPG and RANKL levels in culture solution. Fluorescence quantitative real-time PCR （FQ-PCR） was used to detect the expression of OPG and RANKL mRNA. After three consecutive passages, more than 95% of the primary synovial cells became long spindle fibroblast-like cells. SABC staining results showed that the fibroblast-like cells were negative for anti-CD68 antibody and positive for anti-vimentin antibody, with brown madder stained. CCK-8 test demonstrated that the absorbance （A） value at 450 nm was significantly lower in IL-6R antibody group than in PMMA group and control group （P〈0.01）, but there was no statistically significant difference in A value at 450 nm between the control group and PMMA group （P〉0.05）. Re- suits of ELISA indicated that the expression of OPG was significantly higher in IL-6R antibody group than in PMMA group and control group （P〈0.01）. The expression of RANKL was inhibited （P〈0.05）, and the ratio of OPG/RANKL was significantly increased in IL-6R antibody group as compared with PMMA group and control group. There was no significant difference in the expression of OPG between control group and PMMA group （P〉0.05）, but the expression of RANKL was higher in PMMA group than in control group （P〈0.05）, and there was a significant difference in the ratio of OPG/RANKL be- tween them （P〈0.05）. Results of FQ-PCR revealed the expression of RANKL mRNA was significantly inhibited （P〈0.01） and the expression of OPG mRNA was significantly increased （P〈0.01） in IL-6R an- tibody group as compared with PMMA group and control group. The expression of RANKL mRNA was higher in PMMA group than in control group （P〈0.05）, but the expression of OPG mRNA had no sig- nificant difference between them （P〉0.05）. IL-6R antibody could significantly increase the expression of OPC~ but inhibit the expression of RANKL, which might provide a theoretical basis of molecular bi- ology for the prevention and treatment of aseptic loosening of prosthesis.

Effect of Aβ protein on inhibiting proliferation and promoting apoptosis of retinal pigment epithelial cells

AIM： To identify the effect and regulatory mechanism of amyloid β （Aβ） protein on retinal pigment epithelial （RPE） cells in cell proliferation and apoptosis, and clarify Aβ role in the pathogenesis of age-related macular degeneration （AMD）. METHODS： The model of Aβ25-35 protein cytotoxicity in RPE cell was successfully established to investigate the effect of Aβ protein on RPE cells in vitro. Based on Aβ protein, the specific inhibitors （HY-50682 or BAY11-7082） or activating agent （lipopolysaccharide） was used to analyze the regulatory mechanism of Aβ protein to RPE cells on cell proliferation and apoptosis by flow cytometry, real-time polymerase chain reaction, Western blotting, enzyme-linked immunosorbent assay and dual-luciferase reporter gene assay. RESULTS： The number of RPE cells, treated with Aβ25-35 from 0.3 to 60 μmol/L, significantly reduce （P〈0.01）, and had the dose-dependent effect. Aβ protein 60 μmol/L inhibits the G1/S phase transition （P〈0.01） and down-regulated cyclin E mRNA level （P〈0.01）. Similarly, Aβ25-35 induced a significant increase of cell apoptosis, accompanied by the significantly higher level of activated caspase 3 protein. Furthermore, nuclear factor-kappaB （NF-κB） activity and hosphorylated Iκ-Ba level would significantly lower in treated RPE cells. Using specific inhibitors or activating agent based on the Aβ, the cell numbers, NF-κB activity, phosphorylated Iκ-Ba level, receptor for advanced glycation endproducts （RAGE） gene expression levels, cyclin E mRNA level and activated caspase 3 level had accordingly changed by different methods, confirming that RAGE/NF-κB signaling pathway involved in the regulation of Aβ protein on RPE cell apoptosis and proliferation. CONCLUSION： Aβ protein inhibits cell proliferation and activates apoptosis via inactivation of the RAGE/NF-κB signaling pathway in RPE cell.

Losartan reduced connexin43 expression in left ventricular myocardium of spontaneously hypertensive rats

Objective:To assess the effect of angiotensin II type 1(AT1)receptor antagonist losartan on myocardium con- nexin43(Cx43)gap junction(GJ)expression in spontaneously hypertensive rats(SHRs)and investigate possible mechanisms. Methods:Sixteen 9-week-old male SHRs and 8 age-matched male Wistar-Kyoto(WKY)rats were included in this study.SHRs were randomly divided into two groups to receive losartan at 30 mg/(kg·d)by oral gavage once daily for 8 weeks(SHR-L)or vehicle(0.9%saline)to act as controls(SHR-V);WKY rats receiving vehicle for 8 weeks served as normotensive controls.At the end of the experiment,rats were sacrificed and the hearts were removed.Expressions of Cx43 and nuclear factor-kappaB p65 (NF-κB p65)proteins in all three groups were observed and further investigations on the effect of angiotensin II type 1 receptor antagonist losartan(30 mg/(kg·d),8 weeks)on Cx43 expression were conducted with Western blot and immunohistochemistry. NF-κB p65 protein in nuclear extracts was determined by Western blot.Results:Left ventricular(LV)hypertrophy was prominent in SHRs,Cx43 and NF-κB p65 protein expressions were obviously upregulated and Cx43 distribution was dispersed over the cell surface.Treatment with losarton reduced the over-expressions of Cx43 and NF-κB p65 in LV myocardium.The distribution of Cx43 gap junction also became much regular and confined to intercalated disk after losartan treatment.Conclu- sion:Cx43 level was upregulated in LV myocardium of SHR during early stage of hypertrophy.Angiotensin II type 1 receptor antagonist losartan prevented Cx43 gap junction remodeling in hypertrophied left ventricles,possibly through the NF-κB pathway.

Chronic Oral Administration of Magnesium-L-Threonate Prevents Oxaliplatin-Induced Memory and Emotional Deficits by Normalization of TNF-a/NF-j B Signaling in Rats

Antineoplastic drugs such as oxaliplatin(OXA)often induce memory and emotional deficits.At present,the mechanisms underlying these side-effects are not fully understood,and no effective treatment is available.Here,we show that the short-term memory deficits and anxietylike and depression-like behaviors induced by intraperitoneal injections of OXA(4 mg/kg per day for 5 consecutive days) were accompanied by synaptic dysfunction and downregulation of the NR2 B subunit of N-methyl-Daspartate receptors in the hippocampus,which is critically involved in memory and emotion.The OXA-induced behavioral and synaptic changes were prevented by chronic oral administration of magnesium-L-threonate(L-TAMS,604 mg/kg per day,from 2 days before until the end of experiments).We found that OXA injections significantly reduced the free Mg~(2+) in serum and cerebrospinal fluid(from ~0.8 mmol/L to ~ 0.6 mmol/L).The Mg~(2+) deficiency(0.6 mmol/L) upregulated tumor necrosis factor(TNF-α) and phospho-p65(p-p65),an active form of nuclear factor-kappaB(NF-κB),and downregulated the NR2 B subunit in cultured hippocampal slices.Oral L-TAMS prevented the OXA-induced upregulation of TNF-α and p-p65,as well as microglial activation in the hippocampus and the medial prefrontal cortex.Finally,similar to oral L-TAMS,intracerebroventricular injection of PDTC,an NF-κB inhibitor,also prevented the OXAinduced memory/emotional deficits and the changes in TNF-α,p-p65,and microglia.Taken together,the activation of TNF-α/NF-κB signaling resulting from reduced brain Mg~(2+) is responsible for the memory/emotional deficits induced by OXA.Chronic oral L-TAMS may be a novel approach to treating chemotherapy-induced memory/emotional deficits.

β-funaltrexamine differentially modulates chemokine and cytokine expression in normal human astrocytes and C20 human microglial cells

Aim: Emerging evidence implicates astrocyte/microglia dysregulation in a range of brain disorders, thereby making glial cells potential therapeutic targets. The novel anti-inflammatory actions of beta-funaltrexamine (β-FNA) are of particular interest. β-FNA is a derivative of naltrexone, and recognized as a selective, irreversible antagonist at the mu-opioid receptor (MOR). However, we discovered that β-FNA has novel anti-inflammatory actions that seem to be mediated through a MOR-independent mechanism. Thus far, we have focused on the acute effects of β-FNA on inflammatory signaling.Methods: The effect of β-FNA treatment on interleukin-1β (IL-1β)-induced inflammatory signaling in normal human astrocytes (NHA) and C20 human microglial cells. Cytokine/chemokine expression was measured using ELISA, and nuclear factor-kappaB (NF-κB) p65 activation was evaluated by immunoblot. Results: IL-1β-induced interferon-γ inducible protein-10 (CXCL10) production in NHA was more sensitive to chronic (3 day) β-FNA as indicated by an approximately 3-fold lower EC50 compared to that observed in acutely treated cells. Chronic β-FNA did not affect IL-1β-induced monocyte chemoattractant protein-1 (CCL2) or IL-6 production in NHA. β-FNA inhibited phosphorylation of NF-κB p65, suggesting that the inhibitory effects may be due in part to reduced NF-κB activation. We showed for the first time that C20 human microglial cells were insensitive to the anti-inflammatory actions of acute β-FNA. Conclusion: β-FNA differentially affects inflammatory cytokine/chemokine expression in human astrocytes and microglia. These findings warrant further investigation into the novel anti-inflammatory actions of β-FNA, with a particular focus on astrocytes. These insights should contribute to the development of strategies to treat brain disorders that involve neuroinflammation.